Moisture indicator cap for refrigerant systems



1965 E. s. CHATLOS 3,225,555

MOISTURE INDICATOR CAP FOR REFRIGERANT SYSTEMS 2 Sheets-Sheet 1 Filed Sept. 26, 1963 zEmzExw INVENTOR. EDWARD S- OHATLOS (3. Maw-$5 A? craggy Dec. 28, 1965 s CHATLOS 3,225,555

MOISTURE INDICATOR CAP FOR REFRIGERANT SYSTEMS Filed Sept. 26, 1965 2, Sheets-Sheet 2 m DRY (MK) (BLUE) ....II.I Iii INVENTOR.

E DWARD S. CHATLO 5 United States Patent 3,225,555 MOISTURE INDICATOR CAP FOR REFRIGERANT SYSTEMS Edward S. Chatlos, Morris Plains, N.J., assignor to The Mclntire Company, Livingston, NJ., a corporation of New Jersey Filed Sept. 26, 1963, Ser. No. 311,906 5 Claims. (Cl. 62-129) This invention relates in general to refrigerant fluid conducting systems, and has particular reference to means connected in such a system to indicate the presence therein of undesired moisture in suspension in the fluid stream.

Prior to my present invention, it has been the usual practice to provide the system with an indicator device of the general type disclosed in my co-pending United States patent application Serial Number 192,247, filed May 3, 1962, now Patent No. 3,108,566, and entitled Liquid-Moisture Indicator. An indicator of this type is capable of serving more than one purpose and necessarily includes a comparatively large-diameter hollow body, which is connected directly in the refrigerant conducting pipe line of the system in such a manner that the main stream of refrigerant fluid in its entirety flows through the said body. The size of the instrument body must be sufiicient to permit installation of a large window in one lateral wall. Positioned preferably in flat contact with the central portion of the window is a smalldiameter paper disk which is impregnated with a chemical substance that will cause this so-called color dot disk to change color when contacted by water or other moisture which may happen to be in suspension in the refrigerant flowing through the line. The tiny color dot disk is surrounded by a large expanse of unmasked window through which any gas bubbles indicating a restriction in flow or shortage of the primary refrigerant liquid will be clearly visible.

The desirability of such a dual-purpose indicator is counteracted by certain inherent disadvantages. For instance, when oil in suspension in the refrigerant stream becomes absorbed by the paper color dot disk, the latter will become seriously clogged and finally cease to function as a moisture indicator. When this occurs, the only remedy is complete replacement of the paper disk and its retaining means, but replacement is extremely troublesome. In order to gain access to the paper disk in my cited Liquid-Moisture Indicator, a screw plug must be removed from an opening in one side of the instrument body. This cannot be done without exorbitant loss of refrigerant through the opening except by preceding withdrawal of the screw plug by a pump-down of the fluid in the system, which is very annoying and puts the system out of Working order for an undesirable length of time.

With the above-enumerated disadvantages of the prior art moisture indicators in mind, it has been my purpose to devise one which permits replacement when necessary with little or no loss of refrigerant fluid and without any pump-down procedure. To be more explicit, my proposed moisture indicator is not intended to reveal the presence of gas bubbles in the refrigerant stream. This still must be accomplished by provision of a large-area clear window. In other words, my new indicator is intended merely to supplement any bubble viewing window which may be employed.

When seeking a solution to my problem, it occurred to me that a refrigerant system customarily has more than one charging port located at various convenient points in the fluid conducting line. Each of these charging ports is constituted by a tiny standard male SAE fitting that is admirably suited to use in connecting a small moisture indicator in what may be termed parallel ice relation to the line, as distinguished from the series connection of my above-cited dual-purpose Liquid-Moisture Indicator.

It, therefore, is the primary object of my invention to provide a miniaturized moisture indicator cap adapted to be applied to a selected standard male SAE fitting of a refrigerant system in replacement of its usual seal cap to supplement any bubble viewing device in use at the time. For instance, if the moisture indicating color dot disk of a dual-purpose Liquid-Moisture Indicator already installed in the line has become unserviceable due to oil-clogging, this partially defective indicator may be retained in the line for bubble detection, because the moisture indication function can be performed satisfactorily by one of my moisture indicator caps.

Incidentally, an important advantage of my tiny indicator cap is its low cost as compared with that of the comparatively massive dual-purpose device covered by my cited co-pending application. Actually, the dualpurpose indicator for installation in a refrigerant pipe line of three-eighths inch inside diameter costs $2.50 as compared with my new moisture indicator cap, which costs only 50 cents. Consequently, it is very economical to discard any defective indicator cap and replace it with a new one instead of renewing the oil-clogged paper indicator disk.

Due to the fact that some types of standard male SAE fittings include a check valve to prevent leakage of refrigerant from the line when the seal cap is removed but permit pressurized charging of the line after removal of the cap, it is a further object of the invention to provide one embodiment of my moisture indicator cap with means to open the valve of such a modified fitting automatically upon application of the indicator cap to the latter.

If a refrigerant liquid line is fitted with a single moisture indicator that contains a color-change paper element, the moisture content of the fluid medium being checked can be established only as being either above or below the moisture sensitivity of the paper element in contact with the fluid. However, by utilizing two or more moisture indicators, each having different fixed levels of moisture color change values, a specific range or analysis of the moisture content can be established for the fluid medium in contact with the several indicators.

Therefore, it is also an object of the invention to provide an improved moisture analyzer which includes a manifold constructed and arranged for connection to a standard male SAE fitting in the same manner that one of my single indicator caps is applied thereto but which has plural male SAE fittings of its own to which two or more individual moisture caps of the kinds mentioned above may be applied.

Still further objects, advantages and features of the invention will become apparent as the following specific description is read in connection with the accompanying drawings, in which:

FIG. 1 is a semi-diagrammatic view of a typical refrigerant system, showing the several variously located standard male SAE fittings which serve as charging ports and have standard seal caps applied thereto; and FIG. 2 is a large-scale fragmentary axial sectional view of the refrigerant pipe line and one of the standard male fittings having the standard seal cap threaded thereon.

FIG. 3 is a view similar to FIG. 2 showing a special moisture indicator cap constructed in accordance with the present invention applied to the male fitting in replacement of the usual seal cap; FIG. 4 is an enlarged axial section of the said special moisture indicator cap alone; and FIG. 5 is an outer end view of the cap shown in FIG. 4.

FIG. 6 is a fragmentary axial sectional view similar to FIG. 3, showing a check-valve type fitting with a modified special moisture indicator cap having a depressor plunger adapted to open the fitting valve when said cap is screwed on; FIG. 7 is a transverse section of the modified special moisture indicator cap shown in FIG. 6 taken on line 77 in FIG. 6.

FIG. 8 is an axial vertical sectional view of an analyzer manifold having three special moisture indicator caps of the type shown in FIGS. 3 to applied to the male fittings thereof; and FIG. 9 is a similar view of a modified form of analyzer.

Referring now in detail to the drawings, wherein like reference characters designate corresponding parts in the several views, FIG. 1 diagrammatically represents a typical refrigerant system in which it is customary to provide plural charging ports A at variously located points in the pipe line B convenient for recharging the line with additional refrigerant fluid. Each charging port A is constituted by a standard male SAE fitting C of the general construction shown in FIGS. 2 and 3, wherein a tubular body D is affixed in some convenient hermetically sealed maner, as by brazing, to pipe line B in communication with the fluid channel thereof. The outer end portion of body D is provided with male standard SAE screw threads and the usual closure for the fitting C is a small simple seal cap E provided with female standard SAE screw threads that match the threads of said body D. The extreme outer end of body D of fitting C is tapered at D and the bottom of the cap socket is inwardly flared at E so it is usual to employ a soft copper flare gasket F in interposed relation to the angularly matching tapered end of body D and flared portion of cap E to insure an effective seal. (See FIG. 2.)

In FIG. 3 there is shown a standard male SAE fitting whose usual seal cap has been replaced by the miniaturized special indicator cap 10 of my present invention. This indicator cap is also shown alone in FIG. 4.

Indicator cap 10 is made of any suitable metal, such as plated steel, brass or copper and is substantially cylindrical in shape. A cylindrical through bore 11 extends axially in cap 10 and preferably includes an inner portion 12 of comparatively large diameter that is internally screwthreaded for detachable engagement with the external threads of body D of male fitting C. The outer end portion- 13 of bore 11 is reduced in diameter, and is connected to inner portion 12 by an inwardly flaring intermediate portion 14. A glass window 15 of circular cross section is fused into outer portion 13 of bore 11 by a glass-to-metal compression seal joint preferably produced by the method disclosed in United States Patent No. 3,035,372. In this manner, a hermetically sealed joint between window 15 and cap 10 is created, which wil be capable of withstanding the high operating pressures required, i.e. of the order of 500 to 750 p.s.i.

A color dot moisture indicating element 16 is mounted in contact with the inner face of window 15. This indicating element is a circular disk of paper substantially equal in diameter to window 15 and is impregnated with a chemical substance that causes the disk to change color on a basis of relative saturation when it comes into contact with water or other moisture in suspension in the fluid stream. A commonly employed chemical causes the color to change from blue to pink when moisture is present.

For ease in identifying the moisture condition of the refrigerant, a small color-comparison chart G is located on the outer end face of indicator cap 10 and completely surrounds the viewing window as shown in FIG. 5. The moisture color-comparison code of WET and DRY on this chart will give immediate visual reference to the moisture condition of the refrigerant in the system as the indicating element changes color.

Bearing against the inner face of paper indicating element 16 is a felt disk 17 which is, in its turn, backed by 4 a fine mesh screen disk 18. These disks 17 and 18 are placed there for the purposes of oil removal and retention, but become ineffectual when an excessive amount of oil enters the fluid stream. It is then that the oil-clogged indicating element 16 becomes inoperative to a degree requiring replacement, as previously explained.

Indicating element 16 and cooperative disks 17 and 18 are retained in backing relation to window 15 by the cylindrical outer portion F of flare gasket F described earlier herein. This gasket F permits refrigerant to flow outward into contact with indicating element 16 without external leakage, due to its primary sealing function.

Whenever indicating element 16 becomes inoperative due to oil-clogging, special indicator cap 10 may be unscrewed readily for complete replacement by a new and serviceable indicator cap. Due to the very small bore of standard male SAE fitting C, the loss of refrigerant from pipe line B during the brief cap replacement operation will be negligible. However, there are available, for use in replacement of the simple male fitting shown in FIGS. 2 and 3, a check valve type of fitting such as that disclosed in FIG. 6. This check valve type of fitting C includes a body 19, whose axial bore 20 has an inwardly facing valve seat 21 for cooperation with an inwardly opening valve member 22 that is normally biased into closed position on seat 21 by a spring 23. An operating stem 24 projects outward from valve member 22 in bore 20.

To add greater flexibility to my moisture indicator caps, the simplified form disclosed in FIGS. 3 and 4 has been modified for adaptation to the check valve type of standard male SAE fitting shown in FIG. 6. This modified moisture indicator cap 10', which is shown in detail in FIGS. 6 and 7, is similar in general structure to the FIG. 4 embodiment. Its cylindrical body is provided in the same manner with internal female screwthreads at its inner end for matching engagement with the external male threads of the check valve type of male SAE fitting shown in FIG. 6. In the outer end portion of its axial bore 13', a glass window 15 is fused by the same glassto-metal compression seal joint as that described in connection with the FIG. 4 embodiment; also, the moisture indicating element 16' and respective backing disks 17' and 18' correspond in composition to parts 16, 17 and 18, respectively, of the said FIG. 4 embodiment. The difference between these two moisture indicator caps resides in the valve operating means provided in the FIGS. 6 and 7 modification.

The flare gasket 26, in this modification, is devoid of a cylindrical outer portion and the space occupied by the said portion receives the cylindrical supporting plug 27 for a central depressor plunger 28 adapted to be arranged in axial alignment with operating stem 24 of the valve member 22 of a check valve type male SAE fitting C when a special moisture indicator cap 10' is screwed onto said fitting. Plug 27 preferably is stamped from fiat stock so as to be substantially rectangular in cross-section (FIG. 7) and thereby provide axial side passages 2929 to conduct refrigerant fluid from the bore 20 of fitting C to moisture indicating element 16. Plug 27 is interposed between flare gasket 26 and backing disk 18' of moisture indicating element 16' and is provided with diametrically opposed flanges 27 that bear directly against said backing disk at the margins thereof only so as not to obstruct the mesh interstices of the latter throughout the greater expanse thereof.

When a special moisture indicator cap 10 is screwed onto a check valve type male SAE fitting, depressor plunger 28 will depress valve stem 24 and open the valve to expose moisture indicating element 16' to any moisture which may be carried in suspension in the refrigerant stream.

If a refrigerant liquid line is fitted with a single moisture indicator that contains a color-change paper element, the moisture content of the fluid medium being checked can be established only as being either above or below the moisture sensitivity of the paper element in contact with the fluid. By utilizing two or more moisture indicators, each having different fixed levels of moisture color-change values, a specific range or analysis of the moisture content can be established for the fluid medium in contact with the indicators.

Due to the simplicity of design, my special moisture indicator cap can be utilized easily in a moisture analyzer for a fluid medium, as illustrated in FIG. 8, wherein a tubular manifold 30 having a bore 31 that is closed at one end has its opposite inlet end 32 provided with internal female screwthreads matching those of each standard male SAE fitting C or C in a conventional refrigerant system, thus making it practicable to connect the said manifold to the latter. Manifold 30 is shown provided with three longitudinally spaced attaching sockets 33 in its lateral wall. Each socket 33 is adapted to receive the inner end of a standard male SAE fitting C, with a soldered sealing joint. To complete the analyzer, a moisture indicator cap 10 is screwed onto the outer end of each male fitting C, thereby connecting all three indicator caps in parallel. Each moisture indicator cap 10 contains a moisture-sensitive paper indicating member 16 differing from those of the other caps, thereby providing means for analyzing the moisture content of the refrigerant fluid medium.

Incidentally, when it is desired to apply the analyzer disclosed in FIG. 8 to a male SAE fitting of the check valve type, a supporting plug 27 and integral depressor plunger 28 (FIG. 6) may be screwed into inlet end 32 of manifold 30 before the latter is applied to the said male fitting.

FIG. 9 discloses a modified form of analyzer manifold which can be utilized to permit installation directly in a refrigerant fluid line. With one exception to be described presently, the construction of the modified analyzer is identical with the device shown in FIG. 8. A tubular manifold 30' with a longitudinal bore 31' has an internally screwthreaded inlet opening 32' at one end. Three longitudinally spaced sockets 33' in communication with bore 31 are provided for reception of the base ends of standard male SAE fittings C, with which three moisture indicator caps 10 having respectively different moisture indicating paper disks are operatively engaged. The difference between the FIG. 8 construction and that shown in FIG. 9 resides in the outlet opening 34 P vided in the end of bore 31' opposite to inlet opening 32 in axial alignment therewith. Outlet opening 34 constitutes a socket for connection to a standard male SAE fitting C adapted to be engaged with the internally screwthreaded female opening in the downstream section of the refrigerant pipe line (not shown).

Inclusion of the moisture analyzer embodiments of my invention in the disclosure should further reveal its great versatility. In addition to the advantages of the invention enumerated in the preamble to this specification, there are the following, viz: (1) one size of moisture indicator cap can be used on all sizes of refrigerant systerns, regardless of line size; (2) the low cost of the tiny indicator caps allows more frequent changes on systems where the circulating oil in the refrigerant is likely to contaminate and eventually discolor the indicating paper element; (3) due to the simplicity of design, the moisture indicator caps can be placed conveniently at different locations in the refrigerant system for moisture monitoring; (4) also due to the simplicity of design, the moisture indicator caps can be supplied in all of the standard SAE fitting sizes, if required; and (5) the moisture analyzer, in any of its embodiments, can be assembled easily in the field, utilizing standard connections.

While the invention has been illustrated and described with respect to a few particular embodiments thereof, it will be understood that it is intended to cover all changes and modifications of the embodiments shown which do not constitute departments from the spirit of the invention and scope of the appended claims.

I claim:

1. In a refrigeration system, the combination of:

a refrigerant conducting pipe line;

a pipe fitting in lateral communication with the pipe line and being in the form of a standard male SAE fitting having a bore of a small diameter and being provided with screw threads;

an interchangeable moisture monitoring attachment adapted to be threaded to the pipe fitting and including a hollow manifold casing having an attaching inlet in a wall thereof provided with female screw threads matching the threads of the standard male SAE fitting;

plural standard second male SAE fittings provided exteriorly on said manifold casing in communication with the interior thereof;

plural moisture indicator caps for application to the respective second male SAE fittings of the manifold casing;

each of said moisture indicator caps including a cylindrical body having an inner end open and provided with female screw threads matching the external threads of a corresponding male second SAE fitting and with a window in an outer end thereof, a sight glass covering said window, a moisture indicating element positioned adjacent to said sight glass within the cap body for exposure to refrigerant flowing through the pipeline, and means to retain the moisture indicating element in the exposed position;

and wherein the respective moisture indicating elements differ one from the other in that they are responsive to diiferent moisture proportions of the refrigerant.

2. A device for indicating the moisture content in a fluid transmission line comprising:

a hollow casing adapted to be secured at one end thereof in fluid-communicating relationship with the fluid transmission line;

a plurality of hollow cylindrical bodies each secured at a first end therof in fluid-communicating relationship with the hollow casing;

each of the cylindrical bodies having a transparent sight glass at a second end thereof;

a moisture indicating element within each of the cylindrical bodies adjacent the sight glass;

and means for retaining each of the moisture indicating elements at a predetermined position at which it is exposed to fluid flowing through the fluid transmission line;

the moisture indicating elements differing one from the other in that they'are responsive to different moisture proportions of the fluid.

3. The device of claim 2 wherein:

each of the hollow cylindrical bodies comprises a lower portion defining the first end and an upper portion defining the second end;

each of the moisture indicating elements being included in the upper portion of its respective cylindrical body;

means for controlling fluid transmission from each lower portion to each upper portion comprising a valve seat and a valve in each lower portion;

an axially extending stem connected to each valve;

each of said upper portions comprising means for depressing a respective stem and for removing the corresponding valve from the valve seat, thereby permitting fluid to flow from the lower to the upper portions;

and means comprising a spring for biasing the valve against the valve seat, thereby restricting fluid flow from the lower portion to the upper portion when the upper portion is removed.

4. In combination:

a fluid transmitting line defining a first channel;

means comprising a hollow body for defining a second channel in communicating relationship with the first channel;

said hollow body comprising a lower portion secured to the fluid transmitting line and an upper portion removably attached to the lower portion;

a moisture indicating element in the upper portion;

means for controlling fluid flow in the second channel comprising a valve which is axially movable between a lower open position and an upper closed position;

an upwardly extending stern connected to the valve;

means comprising said upper portion for depressing said stem and for axially moving the valve to its open position;

and means comprising a spring for axially biasing the valve toward its closed position, whereby the valve is moved to its closed position upon removal of the upper portion of the hollow body.

5. The combination of claim 4 further comprising:

a transparent sight glass mounted in one end of the upper portion;

the moisture indicating element abutting against the sight glass;

a retaining element abutting against the moisture indicating element;

a plug abutting at one upper end against the retaining element and at a lower end against the stem;

the upper portion being in threaded engagement with the lower portion;

and the length of the stem being longer than the distance between the lower end of the plug and the closed position of the valve, whereby the valve is displaced from its closed position when the upper portion is in threaded engagement with the lower portion.

References Cited by the Examiner UNITED STATES PATENTS 2,844,026 7/1958 Wischmeyer 62-125 3,085,424 4/1963 Berg 62-125 3,100,691 8/1963 Jones 116-117 MEYER PERLIN, Primary Examiner. 

1. IN A REFRIGERATION SYSTEM, THE COMBINATION OF: A REFRIGERANT CONDUCTING PIPE LINE; A PIPE FITTING IN LATERAL COMMUNICATION WITH THE PIPE LINE AND BEING IN THE FORM OF A STANDARD MALE SAE FITTING HAVING A BORE OF A SMALL DIAMETER AND BEING PROVIDED WITH SCREW THREADS; AN INTERCHANGEABLE MOISTURE MONITORING ATTACHMENT ADAPTED TO BE THREADED TO THE PIPE FITTING AND INCLUDING A HOLLOW MANIFOLD CASING HAVING AN ATTACHING INLET IN A WALL THEREOF PROVIDED WITH FEMALE SCREW THREADS MATCHING THE THREADS OF THE STANDARD MALE SAE FITTING; PLURAL STANDARD SECOND MALE SAE FITTINGS PROVIDED EXTERIORLY ON SAID MANIFOLD CASING IN COMMUNICATION WITH THE INTERIOR THEREOF; PLURAL MOISTURE INDICATOR CAPS FOR APPLICATION TO GHE RESPECTIVE SECOND MALE SAE FITTINGS OF THE MANIFOLD CASING; EACH OF SAID MOISTURE INDICATOR CAPS INCLUDING A CYLINDRICAL BODY HAVING AN INNER END OPEN AND PROVIDED WITH FEMAL SCREW THREADS MATCHING THE EXTERNAL THREADS OF A CORRESPONDING MALE SECOND SAE FITTING AND WITH A WINDOW IN AN OUTER END THEREOF, A SIGHT GLASS COVERING SAID WINDOW, A MOISTURE INDICATING ELEMENT POSITIONED ADJACENT TO REFRIGERANT GLASS WITHIN THE CAP BODY FOR EXPOSURE TO REFRIGERANT FLOWING THROUGH THE PIPELINE, AND MEANS TO RETAIN THE MOISTURE INDICATING ELEMENT IN THE EXPOSED POSITION; AND WHEREIN THE RESPECTIVE MOISTURE INDICATING ELEMENTS DIFFER ONE FROM THE OTHER IN THAT THEY ARE RESPONSIVE TO DIFFERENT MOISTURE PROPORTIONS OF THE REFRIGERANT. 